Blower wheel construction



A. W. EVANS BLOWER WHEEL CONSTRUCTION Filed Sept. 13, 1939 INVENTOR ADDISON W. EVANS BY M A ATTORN if? v Patented Oct. 7, 1.941 r Y 2,25s,o50

Addisonw. Evans, The Torrington Torrington, Conm, assignor Manufacturing 00., Tonington, Conn, a corporation or Connecticut Application September 13, 1939; Serial No. 294,625

Claims. (Cl. 230-434) This invention relates to improvements in blower wheel construction,-and more particularly to improvements curement of a blade-carrying wheel body of sheet or strip metal, to the end rings or back plates of the wheel.

comparatively recent improvements in the manufacture of centrifugal blower wheels, have resulted in the production of a unitary body of the wheel or rotor, characterized in that a single strip, or one of very few elements, is punched or stamped to define the individual blade elements, which are, incident to the same or a subsequent process shaped and bent out of the curved plane of the body to form the individual blade elements of the rotor orwheel. Blower wheels of this general type are sometimes characterized by a curved blade-forming body of sheet metal which is of a somewhat lighter gauge than the back' plate or end ring elements supporting the strip .at its opposite'margins. The securement of blade bodies of the type referred to, to the end ring's, has heretofore in some cases been accomplished by welding, riveting orother manual operations, which-tend to disturb the dynamic and running balance of the wheel structure due to the fact that the securement operations are usually manually effected. It is to the general improvement of blower wheels or centrifugal rotors of the general typereferred to, that the present invention has its major objective which may be stated as attained in an improved balance of wheelsof the type referred to; a greater certainty of uniform securement of the blade-forming body, to the blade carryin elements; a reduction in production cost and simplification of mechanical assembly operations, and the accomplishment of the foregoing "without adding materially to the weight of the wneel or rotor at undesirable points thereon, and withoutv increasing, undesirably, any of the dimenin the provision for selowing detailed description of certain presently sions of the wheel or rotor incident to the adop-- tion of the improved securement means.

Yet another object of' the invention, more particularly stated, is attained in avoidance of the former difliculties arising out of riveted assemblies, in that the rivets cannot always be uniformly spaced, with the result that the blades are not in all cases parallel or evenly disposed at the desired angle.

An additional object akin to those noted, is attained in the construction of centrifugal impellers or blower wheels which v utilize anovel and I simple means for securement of the blade structure to the back plates. or end rings in a unithroughout the wheel, whereby to dynamic balance of the form manner improve the running and finished wheel.

The foregoing and invention will more clearly still further objects of the appear from the, folpreferred embodiments of the invention, considered in connection with the accompanying drawing, in which:

Fig. 1 is an elevationin perspective of a centrifugal blower wheel, constructed in accordance with my invention; Fig. 2 is an enlarged fragmentary, end view, showing a portion of a bladeforming strip of the wheel, near one end margin of the wheel or side margin of the strip; Fig. 3 is a fragmentary end elevation of the peripheral part of one of the in a radial plane, showportion of part of the is a fragmentary section ing sectionally, one end blade-carrying strip or portion of one end'ring; Fig. 5 is a view taken similarly to Fig. 4, showing a somewhat modified form of assembly, and Fig. 6 is a view taken similarly to Fig. 4 showing a still further slightly v of a relatively heavy gauge sheet metal. The end ring ill includes. a central annulus or disc ll, provided with bolt holes l2 for securement to a wheel hub, the hub engaging the shaft (not.

shown) on which the wheel or rotor is-mouiited. Projecting. radially from the disc II, are a plurality of arms or spokes l3, by the'outer ends of which is carried a rim ll of the end ring, and

which serves as will hereinafter better appear, as the immediate support for the blade-forming body or strip.

For convenience has been referred to as an end ring, but it will be understood that the present improvements are equally adapted to a structure in which at least one of the blade-supporting elements is a substantially imperforate structure or back plate,

e'nd rings, with. the blade carrying strip secured thereto; Fig. 4

body and the adjacentindicated generally at H), and consisting as shown, of a one-piece punching or stamping the bladecarrying structure I as might be employed in certain cases in the event the present improvements are utilized with a so-called single inlet impeller or wheel.

According to present preference, and with the distinctpurpose of obviating any increase in axial dimension or length of the wheel by reason of the securement of the body to the end rings or plates, it is a preference that the end ring Ill be formed to lie substantially in a given flat the blade-carrying strip or body to the end rings.

Inasmuch as the general method of formation of the blades is fully set forth in the copending application to which attention is directed, it need not be described in any more detail than to note.

as a preference that the body lie substantially in a curved plane, being shaped substantially as a curved surface of a cylinder. By a single punching or stamping operation, or a succession thereof, the individual blades are produced from the initially flat strip by slitting the strip transversely thereof with the slits in substantially parallel arrangement, so that the body-forming element is, when thus punched, characterized by-a plurality of substantially portions defined by edges 20 and 2|. The metal between these edges is either by the same or subsequent punching or stamping operations, bent to a substantially arcuate section on a relatively small radius. It results from this that the finished rotor presents a plurality of spaced blades 23 extending transversely of the body-forming strip.

Each side margin of the body-forming strip as indicatedgenerally at 24 (Fig. 1), is characterized by an imperforate margin 25'which provides a circular flange at each end of the series of formed blades. Beyond each marginal portion 25, a free edge or outer marginal portion 26 is bent parallel transverse strip ing body, on the outside of the portions l4 aasaoso that these pockets provide a deflnitemetering provision for the metal employed in the body flange 26 and the adjacent end ring. The uniformity of metal in the spaced zones defined by these pockets, assures a highly uniform loading of different parts of the wheel, and hence assures gooddynamic and running balance.

Optionally, but with some preference, the assembly of the strip metal body to the end rings is further cared for by a line weld, the location of which is indicated at Si in respect to the structure of Figs. 1, 2, 3 and -4. In the event the line weld such as 3i, is used to augment the securement eifected by the metal elements 32 in the pockets 30; it is preferred but not absolutely necessary, that the line of welding metal be applied first, andthe pockets filled by the uniting metal, as a subsequent operation.

In the preferred structure such as shown by Figs. 1, 2, 3, and 4, assembly is preferably effected by location of the flanges 28 on the blade-carryoi the end rings l0, as will best appear from Figs. 3 and 4. This arrangement offers some advantage in the fact that the outer peripheral edge of the 1 ring serves as a seat for the inner surface of the body strip, which facilitates assembly. It may, however, be noted as entirely practical and within the realm of present improvements to dispose the flange 26 inwardly of the annular peripheral .portion I4 of the end rings, as shown by Fig. '5.

at substantially a right angle to the curved plane of the body of the wheel, specifically at a right angle to the adjacent imperforate marginal part such as 26, is bent radially inwardly, or downwardly of the curvedplane of the blade-carrying uniformity of secureinent and to enhance the planar aspect of this portion in assembly, to

provide it with a pluralityof indents or notches 30. These are preferably of triangular shape as shown, and may be formed as by punching, in the same operation or series thereof, which result in the blade formation in the body of the wheel. It-will appear, particularly from Fig. 3, that the indents 30 serve, when the flange 26 is brought into assembled relation to the periphery H of the endring, as pockets for the reception of an assembly metal, such as welding or brazing materials, solder or the like.

The pockets 30 are or may be formed uniformly by suitable punching dies, and so are of uniform area and but for any inconsiderable variation in 25. According to preference, this flange or lip,

gauge. of metal in the blade-forming body, are of uniform depth. Being evenly angularly spaced In this case a line weld 33, if utilized, will be .located on the inner surface of the ring, which offers some advantage from the point of view of appearance. It will be understood that the pockets 30 for solder or. the like, are similarly provided, but that such pockets will then be 10- sated over the inside planar surface of the adjacent ring portion M.

A somewhat further modification within the scope of the present improvements is shown by Fig. 6, wherein the body strip 34 is provided with blades 35 integral therewith, and which maybe the same as blades 23, heretofore described, the body strip being provided with marginal flanges 36. In this modification however, the flanges 36 are turned upwardly or outwardly of the curved plane of the wheel body, rather than downwardly therefrom as in the structures heretofore described. By preference the flanges 36 are provided with pockets or the like (not shown) which are or may be the same as those indicated at 30 (Fig. 3). In the construction exemplified by Fig. 6, in the event a line weld be employed, together with the pockets containing a uniting metal to augment the securement efiect thereof, a weld line may be located as shown at 3'! (Fig. 6).

It 'will have appeared that in any of the arrangements of Figs. 4, 5 or 6, the serrated flange turned outwardly of the curved planeof the sheet metal body, lies closely parallel to the adjacent surface of the planar end ring, and that in any of these constructions the securing and assembly means are confined substantially between the planes of the end rings or back plates without requiring any addition to overall length, as is the case with certain asssembly expedients heretofore employed. n

It will appear as a distinct production advantage of the present wheel, that it may be formed entirely of no more than three metal elements, excluding the soldering or welding materials em-' ployed, the major elements being, respectively, the two end rings or back plata and the one piece body from which are struck out and formed the individual blades of the rotor.

Although the invention has been described by making specific reference to certain preferred embodiments, certain minor modifications may be made in these parts as well as in their combinations and assembly without departing from the full intended scope of the invention as defined by the claims hereunto appended.

1. A centrifugal blower wheel including a pair of one-piece annular end members, a one-piece cylindrical body provided with parallel blades and disposed substantially between the end members, a flange member at each side margin of the body bent from the plane thereof so as to lie in close parallel adjacence to the annular end members, means by which the body flanges and end members are metallically united at evenly angularly spaced zones near the periphery orvthe wheel, and means constituted by cut-away portions of the periphery of one of the mating members for defining and flxing said zones of metallic union.

2. A centrifugal blower wheel including a pair of end rings, a unitary sheet metal body characterized by integral'blades formed of the metal of the body, a right angle flange on each of the opposite end margins of the body, each of said flanges being characterized by a plurality of evenly spaced angulate indents, a line of welding metal or the-like along the extremity of each of said right angle flanges, serving to secure the free edge of each flange to the adjacent end ring,

and servingwith the flange to form with the indents, a plurality of metal-receiving pockets, and a unit or uniting metal in each of said pockets, coacting with the line of welding metal to position the flange and end rings in assembly.

3. A- three-part centrifugal blower wheel, the elements of which consist of a pair of spaced annular elements constituting end rings or the like, a sheet metal body unit bridging said end rings, the body being characterized by outstruck formed blades, a right angle securement flange at each axial end of the body, each flange being provided along its free margin with a series of 1 evenly spaced v shaped indents or serrations providing pockets for an assembly metal, the outer margins of end rings, a unitary sheet metal body characof the flanges being assembled by a line of assembly metal, engaging both the flanged margin of the strip and the adjacent end ring, and a plurality of units of assembly metal, each occupying one of the pockets formed by and between aid line of welding and the adjacent serrations'on' the margin of the flange.

4. A centrifugal blower wheel including a pair terized by integral bladesformed of the-metal of the body, a right angle flange on each of the opposite end margins of the body, each of said flanges being turned radially outwardly in a manner to lie parallel to the inside peripheral faces of the end rings, each flange being characterized by a plurality of evenly spaced indents along and opening inwardly of the free margins Of the flanges, a line of welding metal or the like along the extremity of each of said right angle flanges, serving to secure the. free edge of each flange to the adjacent end ring, and serving with the flange to form with the indents, a plurality of metal-receiving pockets, and a unit of uniting metal in each of said pockets, coactingwith the line of welding metal to position the flange and end rings in assembly.

5. A centrifugal blower wheel including a pair of end rings, a unitary sheet metal body characterized by integral blades formed of the metal of the body, a right angle flange on each of, the opposite end margins of thebody, each of said flanges being turned radially inwardly or downwardly, so as to lie parallel to and in engagement with the outside peripheral faces of the end rings, each of the flanges being characterized by a plurality of evenly spaced indents along and opening inwardly of the free margins of the flanges, a line of welding metal or' the like along the extremity of each of said right angle flanges, serving to secure the free edge of each flange to the adJacente'nd ring, and serving with the flange to form with the indents, a plurality of metal-receiving pockets, and a unit-of uniting metal in each of said pockets, coacting'with the line of welded metal to position the flange and end rings in assembly. i

v ADDISON W. EVANS. 

